1# Experiment 9 - Effect of temperature and pressure on equilibrium 2 3To determine the effect of the temperature and pressure of an equilirium environment on the direction of the equilibrium reaction. Temperature is tested by adding methyl violet indicator to a solution of phosphoric acid which shows the concentration of ionised H+ and H2PO4- ions. Pressure (inversely proportional to volume) is tested with dinitrogen tetroxide and the colour change is observed. 4 5N2O4(g) <-> 2NO2(g) 6 clear <-> brown 7 8Explain colour changes - net forward/back reaction 92 page question 10Do not duplicate 11 12What was the change to equilibrium system? (do not copy method) 13(1 mark for each test) 14 15Vertical lines on plots 16(selection of graphs) 17 18Reaction conc initially > product conc 19Two marks on x-axis - init. & funal equilibrium 20Rule graphs 21Lines may cross 22 23H33PO4 - each product concentration is equal (dissociation of acid) - one line 24Fe3+ + SCN- - each reactant is not necessarily equal concentration 25 2690 marks total 2717 marks from results 281 mark/box on first question (table)